Risk Factors for CHD- Indications for Fetal Echo Revisited Amy
Svenson, MD Division of Pediatric Cardiology Arizona Pediatric
Cardiology Consultants Phoenix Childrens Hospital Phoenix,
Arizona
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None
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Screening for CHD Congenital heart disease continues to be the
most common congenital malformation, at a rate of ~8/1,000 live
births. Most cardiac defects are screened for on the routine 18-20
week anatomy scan by the OB, but the rates of detection of CHD
remain low At 20 weeks gestation, the fetal heart is a little
bigger than the size of a quarter
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Screening for CHD Cardiac anomalies are among the most
frequently missed congenital malformations and rely heavily on the
expertise of those performing the exam Those specialized physicians
performing and interpreting detailed fetal echocardiograms can
detect nearly all cases of CHD, but they are a very limited
resource Thus, much research has gone into identifying markers for
CHD outside of the detailed fetal echocardiogram
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Screening for CHD Maternal patients may be referred for a
detailed fetal echocardiogram by a qualified specialist if: the
basic screening ultrasound is abnormal Concern for structural heart
defect Concern for abnormal heart rhythm there is a recognized risk
factor that raises the likelihood of congenital heart disease
beyond what is expected in the low risk population
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Which patients are considered to be at increased risk and thus
should be referred for a detailed fetal echocardiogram?
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Fetal indications suspected cardiac anomaly or abnormal cardiac
axis incomplete cardiac evaluation on OB screening ultrasound
Unexplained polyhydramnios chromosomal abnormalities extracardiac
abnormalities Arrhythmias (50% of fetuses with CHB have complex
CHD) non-immune fetal hydrops (15-20% are of cardiac etiology)
increased nuchal translucency Monochorionic twins
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Maternal indications Maternal metabolic disorders
Pre-gestational diabetes or early onset diabetes during pregnancy
6-10% congenital malformation rate, of which 40-50% are cardiac
Structural defects (TGA, DORV, VSD, heterotaxy syndrome)
Hypertrophic cardiomyopathy (late 2 nd or 3 rd trimester) Maternal
PKU (7 fold increase in CHD)
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Maternal indications Autoantibodies (anti-Ro/SSA and
anti-La/SSB) associated with Sjogren syndrome (40-95%) and SLE
(15-35%) 1-2% risk of complete heart block Recurrence risk of
15-20% Pregnancies conceived with assisted reproductive technology
(ART) Exposure to known teratogens or certain medications
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Familial indications Family history of CHD in a first degree
relative 2-3% recurrence risk if a sibling has CHD 2% recurrence
risk if dad has CHD 5-10% recurrence risk if mom has CHD Left heart
obstructive lesions appear to have a higher recurrence risk
APCC experience * Database collected and managed by Lynn
Litwinowich, APCC fetal nurse coordinator, from January 2011 to
January 2014
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Assisted Reproductive Technology
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ART Fertility related services (artificial insemination,
inductors of ovulation) Removal of a womans eggs from her body,
mixing them with sperm to make an embryo, and then reintroduce them
to the womans body In vitro fertilization/IVF (1978)
Intracytoplasmic sperm injection/ICSI (1992) Represents 1% to 4% of
births in developed countries
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ART First infant born to ART was over 30 years ago (1978) CDC
started collecting data on ART in the US in1996 National data from
the CDC on ART in 2010: 147,260 total ART procedures 47,090 live
births= 61,564 infants ART contributed to 1.5% of all US live
births in 2010 ART contributed to 20% of all multiple births 46% of
infants conceived with ART are multiples
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ART The majority of the more recent population based studies do
show a statistically significant increase in birth defects in
pregnancies utilizing ART versus natural pregnancies. Is this
increased risk due to the ART protocols themselves or the
underlying disturbance leading to a couples infertility? There are
few studies looking at the relationship of specific birth defects
and ART
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ART and the risk of CHD Tarabit, K. et al., Euro Heart J, 2011
Utilizing the Paris Registry of Congenital Malformations Compared
exposure to ART between cases of CHD vs. other malformations in
chromosomally normal infants (picked malformations that have not be
previously reported to be associated with ART) 4.7% of children
born with CHD versus 3.6% of children born with a different
malformation (p= 0.008) were exposed to ART 40% increase in the
overall risk of CHD without chromosomal abnormalities in children
conceived following ART after taking into account maternal age,
socioeconomic factors, and year of birth
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ART and the risk of CHD Specific types of CHD were more
commonly found in children exposed to ART (IVF and ICSI) including:
Malformations of the outflow tracts Abnormalities of the
ventricular-arterial connections Double outlet right ventricle
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ART and risk of all birth defects Davies, M et al., NEJM, 2012
Utilized the Australian registry of births and terminations between
1986 and 2002 Compared 4 group types for identification of major
birth defects up to 5 years of age: 1.ART pregnancies 2.Spontaneous
pregnancy but with a history of a previous ART birth 3.Spontaneous
pregnancy but with a history of infertility (no ART) 4.Spontaneous
pregnancy with no history of infertility
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ART and risk of all birth defects 8.4% of ART pregnancies vs..
5.8% of non-ART pregnancies had a major birth defect present (OR
1.47) The risk is highest for ICSI (OR 1.77) than IVF (OR 1.26)
There is an increased risk of birth defects in pregnancies of women
with history of infertility When comparing pregnancies with
multiples, there was no significant increase in risk of birth
defects ART pregnancies were more likely to have multiple birth
defects Specifically, the risk for cardiovascular, musculoskeletal,
urogenital, GI defects and cerebral palsy had the highest OR.
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ART and risk of all birth defects The increased risk of birth
defects for IVF, but not ICSI, became insignificant when
adjustments were made for maternal age, maternal conditions in
pregnancy, etc.
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ART- the U.S. experience Kelley-Quon, L. et al., J of Ped Surg,
2013 Utilized the California Infant and Maternal Birth Cohort
Dataset (2006-2007) California currently has the highest national
rates of infants born after ART (66% ICSI) No significant increase
in birth defects when using fertility related services (ovulation
induction and artificial insemination) alone
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ART- the U.S. experience After adjusting for maternal and
infant factors, there was an overall increase in birth defects
associated with ART pregnancies when compared with naturally
conceived controls (9% versus 6.6%, p=
Nuchal Translucency Conclusions from Sotiriadis et al.:
Sensitivity and specificity of identifying major CHD if the NT is
>95 th percentile is 44.4% and 94.5% respectively Sensitivity
and specificity of identifying major CHD if the NT is >99 th
percentile is 19.5% and 99.1% respectively The risk for major CHD
is more than 20 times increased if the NT is >99 th
percentile
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NT- pooled data *In general, there was a high heterogeneity in
the data sets
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Maternal obesity
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Maternal Obesity Data from the National Health and Nutrition
Examination Survey, 2011-2012 34.9% of adults were obese in
2011-2012 Highest among middle-aged adults, when compared to
younger and older adults Obesity is higher among certain
ethnicities: black (47.8%) and Hispanic (42.5%) adults
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Imaging for a BMI of 20
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Imaging for a BMI of 65
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Adult Obesity Rate by State, 2012
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Obesity Maternal obesity has long been linked to an increased
risk for infants with neural tube defects Over the last decade,
data is accumulating that also links maternal obesity to infants
with CHD
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Obesity Mills, J, American Journal of Clinical Nutrition, 2010
Maternal BMI in 7,392 infants with CHD and 56,304 controls without
major malformations born during 1993 to 2003 in New York State
Overweight defined as BMI 25-29.9 Obesity defined as BMI >30,
morbid obesity >40 Overweight women(BMI 25-30) were not at an
increased risk to have a child with CHD
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Obesity Findings: Overweight women(BMI 25-30) were not at an
increased risk to have a child with CHD all obese women were
significantly more likely than normal weight women to have a child
with a CHD (OR 1.15) Found an increasing risk of having a child
with CHD with increasing maternal BMI 15% higher risk for all obese
mothers having a child with CHD if the BMI was >30 and a 30%
higher risk if the maternal BMI was >40.
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Obesity Lui et al., Circulation, 2013 Population based cohort
study of all live births in Canada 2002 to 2011 looking the
association of maternal conditions and CHD in their offspring. They
were able to separate out very specific maternal conditions and
specific types of CHD utilizing ICD-10 coding 2.3 million infants
screened with a prevalence of CHD 10/1,000 (excluding PDAs in
preemies) and 2.2/1,000 being severe CHD Maternal conditions
evaluated included: age, tobacco use, substance use, obesity, DM,
HTN, thyroid disorders, CHD, CAD, anemia, connective tissue
disorder, epilepsy
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Obesity CHD prevalence was significantly higher among women
with chronic medical conditions, and specifically with multifetal
pregnancy, DM, CHD and systemic connective tissue disease having
the strongest association Maternal obesity was associated with a
1.5 to 2x greater risk for CHD (consistent with previous
studies)
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Ultimately, the decision of whom to refer for formal fetal
echocardiography should reflect both the perceived likelihood of
fetal heart disease and the additional expertise anticipated from
referral - Mark Sklansky Referenced from Textbook: Creasy &
Resniks Maternal-Fetal Medicine, Chapter 19. Fetal Cardiac
Malformations and Arrhythmias- Detection, Diagnosis, Management and
Prognosis